Hello, I bumped into a problem lately. I started having issue with t5050. My problem is that when I increase rpm and let of the gas immediately, idle rpm fluctuate for about 3 seconds and then settle or when there is a change in load. When I slowly decrease rpm, it doesn't do that. Could it be a problem with injection pump, overflow valve or an air leak at return line?? Maybe it could be just fuel clogged fuel filter? But last time when it did that, I tried to pour in some diesel additive and I think it stopped. I don't think that it might be an issue with fuel quality because my other tractor runs fine with same fuel. Please, do you have any idea what it could be? Maybe fuel pump needs adjusting?? Thanks for reply